From bb64da9aba89765fee74b395967b18a7d6c364e9 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Tue, 21 Nov 2017 16:02:52 +0100 Subject: KVM: s390: mark irq_state.flags as non-usable Old kernels did not check for zero in the irq_state.flags field and old QEMUs did not zero the flag/reserved fields when calling KVM_S390_*_IRQ_STATE. Let's add comments to prevent future uses of these fields. Signed-off-by: Christian Borntraeger Reviewed-by: Thomas Huth Reviewed-by: Cornelia Huck Reviewed-by: David Hildenbrand Signed-off-by: Christian Borntraeger --- arch/s390/kvm/kvm-s390.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'arch/s390/kvm/kvm-s390.c') diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 34375eed93ee..efa439f6ffb3 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -1,8 +1,8 @@ // SPDX-License-Identifier: GPL-2.0 /* - * hosting zSeries kernel virtual machines + * hosting IBM Z kernel virtual machines (s390x) * - * Copyright IBM Corp. 2008, 2009 + * Copyright IBM Corp. 2008, 2017 * * Author(s): Carsten Otte * Christian Borntraeger @@ -3808,6 +3808,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp, r = -EINVAL; break; } + /* do not use irq_state.flags, it will break old QEMUs */ r = kvm_s390_set_irq_state(vcpu, (void __user *) irq_state.buf, irq_state.len); @@ -3823,6 +3824,7 @@ long kvm_arch_vcpu_ioctl(struct file *filp, r = -EINVAL; break; } + /* do not use irq_state.flags, it will break old QEMUs */ r = kvm_s390_get_irq_state(vcpu, (__u8 __user *) irq_state.buf, irq_state.len); -- cgit v1.2.3